Do Corroles Stabilize Tetravalent Antimony?

Abstract

Abstract Antimony corrole cations have been prepared by one‐electron oxidation of antimony(III) congeners with silver(I) and copper(II) salts. Isolation and crystallization was successful for the first time, and the X‐ray crystallographic investigation unraveled structural similarities with antimony(III)corroles. EPR experiments showed strong hyperfine interactions of the unpaired electron with the 121 Sb ( I =5/2) and 123 Sb nuclei ( I =7/2). A DFT analysis supports the description of the oxidized form as a Sb III corrole radical with less than 2 % Sb IV character. In the presence of water or a fluoride source like PF 6 − , the compounds undergo a redox disproportionation to yield known antimony(III)corroles and either difluorido‐antimony(V)corroles, or bis‐μ‐oxido‐di[antimony(V)corroles] via novel cationic hydroxo‐antimony(V) derivatives.